[Patriot Infinity]

Not sure what's going on, but the coolant thing is overheating/sizzling causing the rest of the engine compartment to heat up. Temp gauge doesn't go passed the middle, though. It's 102 degrees here in Vegas and I was driving the car for about an hour or so. Once the car was parked, it began making a loud steaming noise and I noticed some coolant (I think) was dripping out. I took a video of what happened:

https://www.youtube.com/watch?v=CDpsmggb9SY

The video doesn't capture the sound all that well, but it's sizzling loudly. Is this normal? Is there a fix?

 

[Ddaddy]

Not normal at all!

You are "boiling over".

Since it isn't happening when driving, it suggests that your coolant is old and needs to be replaced (boiling point is too low).

When was the coolant replaced?

 

[Patriot Infinity]

So should I take it somewhere or mix new coolant with it? It was last changed almost a year ago I think (I rarely drive the car).

 

[Ddaddy]

I would have it properly flushed, refilled with fresh coolant and pressure tested. You need to make sure all of the air is purged from the system too.

 

[Patriot Infinity]

That sounds mildly expensive. Any specific price range I should expect? I don't want to get ripped.

 

[Ddaddy]

It should generally cost between $140-$180 depending on the labor rates in your area. You may be able to get it closer to $100 if you have a shop you use regularly and they give you a good deal. Labor runs around 1.5 hrs at shop rate plus materials and disposal fees.

 

[Patriot Infinity]

Okay cool. Thanks for the help as usual Ddaddy!

 

[Borg4]

Before you spend $100.00, try this cheap fix, a new radiator cap. When these fail, the spring can't hold the pressure of the heated antifreeze, and releases it to the overflow, which overfills and runs out the overfill hose. Takes 1 minute, and should be way less than $20.00.

Dan

 

[Patriot Infinity]

Before you spend $100.00, try this cheap fix, a new radiator cap. When these fail, the spring can't hold the pressure of the heated antifreeze, and releases it to the overflow, which overfills and runs out the overfill hose. Takes 1 minute, and should be way less than $20.00.

Dan

So don't bother with flushing/replacing the antifreeze?

 

[Borg4]

I am not saying it isn't the coolant, but if you replaced it within the last few years, but still have the original cap, it is a common, overlooked source of overheating and/or losing coolant, and anyone who can fill their gas tank can change a radiator cap. Just wait until the car is cooled off. Best to do it before the first start of the day.

 

[Ddaddy]

I am not saying it isn't the coolant, but if you replaced it within the last few years, but still have the original cap, it is a common, overlooked source of overheating and/or losing coolant, and anyone who can fill their gas tank can change a radiator cap. Just wait until the car is cooled off. Best to do it before the first start of the day.

You're right and it's a good point. It's an easy thing to test first to see if it's blowing off at lower than the rated pressure by simply replacing it.

If it fixes it, you are good to go. I also forgot to mention that you can have your coolant tested by most shops to see what it's condition is using a simple hydrometer tool. Many shops will do it for no charge but the engine must be cool enough for them to safely remove the cap. That means you may have to wait for a while for it to cool down.

It will quickly tell you whether it has degraded and the boiling point is too low. You can also buy the tool from the autoparts store and test it yourself. It's an inexpensive tool.

 

[Patriot Infinity]

I replaced the radiator cap. Will let you know if that wasn't the problem though. Thanks for the help.

 

[barty005]

I replaced the radiator cap. Will let you know if that wasn't the problem though. Thanks for the help.

Very high odds it wont be your coolant that will be the problem most car wont even overheat with straight plain jane water. Id check for radiator blockage thermostat sticking or bad water pump performance.

 

[rodneyiii]

Make sure your cooling fans are working properly since they are a well known problem. It is probably just the rad cap since the temperature didn't go past the normal point. No system pressure will allow the coolant to boil at a much lower temp than when the system has 12-15 lbs. of pressure in it.

 

[Ddaddy]

Folks should remember when giving advice that the car didn't overheat and boil over until it was parked. No issues when driving. That suggests the cooling system was operating normally (thermostat, fans, etc.)

When the pumping system (water pump and coolant flow) and cooling system (fans) were turned off, the car boiled over.

There are only a few things that can cause that.

 

[rodneyiii]

Folks should remember when giving advice that the car didn't overheat and boil over until it was parked. No issues when driving. That suggests the cooling system was operating normally (thermostat, fans, etc.)

False. A car driven at a decent speed that keeps air flowing across the radiator most likely won't overheat even if the fans are dead. Once the car stops moving, the lack of air on the radiator will allow heat to build quickly and potentially overheat the engine.

 

[Ddaddy]

False. A car driven at a decent speed that keeps air flowing across the radiator most likely won't overheat even if the fans are dead. Once the car stops moving, the lack of air on the radiator will allow heat to build quickly and potentially overheat the engine.

Not false. The description was given by the OP and since he describes 102° heat, boil over would have happened before he parked it...Unless he drove 60+ mph all the way to his garage.

One of my fans failed 2 Summers ago in 90° heat and I can tell you it hit 226° in a few minutes at 30 mph. If both fans had failed, it would have over heated in a heartbeat.